isblock
static int isblock(struct fs *, unsigned char *, int);
if (isblock(&sblock, cg_blksfree(&acg),
if (isblock(&sblock, cg_blksfree(&acg),
if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
static int isblock(struct fs *, unsigned char *, int);